Method and apparatus for marking containers using laser light

ABSTRACT

A portion or component of a metal container is provided with markings or indicia using laser light. High-speed laser steering is used to position laser light or laser light pulses across a lateral and longitudinal extent in a relatively short time period such as a time period selected so as to avoid slowing, stopping or otherwise interfering with other container or container component production processes. Preferably, tab stock for container-opening tabs can be provided with 6 to 9 or more visible characters within a time window of 50 to 100 milliseconds or less. Preferably, the size and resolution provided by the pulses are sufficient to permit legible, and preferably attractive, formation of any standard typewriter characters. In one embodiment, other logos, designs, textures, backgrounds and similar features can be provided.

This application is a Divisional of Ser. No. 09/564,429, filed May 4,2000 which is a continuation of Ser. No. 09/116/794, filed Jul. 16, 1998(now U.S. Pat. No. 6,080,958) both incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the use of a laser for markingcontainers including container body end tab portions and in particularto a process that can rapidly achieve the desired amount of markingwithin a predetermined time such as a manufacturing process dwell time.

BACKGROUND OF THE INVENTION

As part of a container manufacturing, or in some cases, filling orsealing operation, markings may be placed on containers for a variety ofpurposes including identifying contents, identifying the location ordate of manufacture or use, identifying the maker of the container orcontainer component, the style or materials for the container, providingof trade names, advertising, promotion, or the like. In some situations,promotional information in the form of sweepstakes, contests, or othervaluable tokens or indicia are placed or marked on container orcontainer components.

A variety of devices and procedures have been used for markingcontainers. In some cases, embossing or incising processes have beenused. Embossing or incising, e.g. via stamping, can require anundesirably large inventory of tools, e.g. for different kinds oflettering or symbols, and typically requires the need to shut down anassembly line and disassemble a press whenever it is desired to changetools (such as for changing the indicia being incised or embossed or formaintenance or repair purposes). Such shutdowns are particularlytroublesome when it is desirable to change the symbols with relativelyhigh frequency, such as when markings on containers are intended as partof a contest or sweepstakes in which there are preferably a relativelylarge number of different possible markings or indicia (e.g. when onlysome of which are “grand prize” winners). Furthermore, it has beendifficult to accurately control the depth of embossing or incising and,in some cases, embossing or incising that is too deep has led to leakageor container failure.

Accordingly, it would be advantageous to provide for marking ofcontainers or components in a fashion permitting markings or indicia tobe changed with relatively high frequency but without the need to stopor slow down a production line for this purpose. It would also be usefulto provide for marking containers while avoiding the need formaintaining relatively large inventories of tools or dies, andpreferably while avoiding container quality problems such as may arisefrom markings which are excessively deep.

Another process which has been used for placing markings on containersor components thereof, has been one or more printing processes. Contactor press printing is sometimes useful for decorating or placing markingson containers where it is desired to place a relatively large number ofidentical markings on containers. However, contact printing is believedimpractical for many components, because of their shape or position(such as container-opening tabs) or when it is desired to change indiciawith relatively high frequency (e.g. for sweepstake or contest purposes)because of the need to stop a production line and partially disassemblethe contact print device in order to change the configuration of theitems being printed on the containers.

In some situations, components of containers may be printed using anon-contact printing process such as an inkjet process. Although inkjetscan be controlled to provide relatively changes in indicia, inkjetprocesses and equipment have been found, in the past, to be relativelyunreliable such as requiring frequent maintenance and repair. Inkjetprocesses have also been found to be subject to unwanted placement orpositioning of ink such as resulting in a mist of ink which caninterfere with the printing process, cause undesired markings on cans,or cause equipment malfunction. In some cases, it has been found that upto 20% or more of potential production time has been lost to the needfor cleaning up, maintenance and/or repair when an ink jet process isused. Additionally, it has been found difficult to achieve reliableadhesion of the ink to containers or container components. Furthermore,when inkjet or other printing processes are used in connection withcontest sweepstakes or providing other valuable tokens or indicia, sincethe process provides only surface markings (without forming indentationse.g. in the container itself) there is an undesirably large potentialfor counterfeiting or altering the markings e.g. in an attempt to claima contest or sweepstakes prize. Furthermore, inkjet processes have beendifficult to provide at high speed while maintaining quality, so as tomark letters or other indicia without distortion or the like.

Accordingly, it would be useful to provide for high quality marking ofcontainers or container components while avoiding the cleanup,maintenance and repair time associated with inkjet or other printingprocesses, preferably while permitting relatively rapid changes ofindicia.

Some or all of the above difficulties in previous container markingprocedures are particularly troublesome for metallic containers orcontainer components such as a typical aluminum alloy beverage container(e.g. of the type available from Ball Corporation, Broomfield, Colo.) ortabs or other components thereof. As compared with, e.g., plastic orcontainer components, metal containers can be relatively difficult tomark, at least because it can be difficult to adhere ink to metalsurfaces, because of the harder surface of metal containers, highermelting or softening point, and the like. Accordingly, devices andprocesses used in connection with some container materials are notnecessarily applicable to others. In most situations, the functions orpurposes for container markings will rarely justify use of procedureswhich would involve expenses which are substantially in excess of thoseinvolved with current processes. Accordingly, it would be useful toprovide for procedures and devices for marking containers which can beachieved economically, preferably without substantially exceeding costsor expenses associated with current container production, filling orsealing processes.

SUMMARY OF THE INVENTION

The present invention provides for using laser light for marking metalcontainers or container components (including, e.g., container bodies,container ends and container end tabs). In one embodiment, a laser isprovided with rapid-acting beam-steering and control to permit themarking of a relatively large number of characters or symbols (such as 6or more, preferably 9 or more) in a relatively short period of time(such as less than about 100 milliseconds, preferably less than a normalcomponent production dwell time e.g. of about 50 milliseconds) so thatthe desired marking can be achieved without stopping or slowing currentcontainer or container component fabrication procedures or machines.

In one embodiment, steering of a laser beam is achieved with highrapidity by reducing the mass of one or more steering mirrors. Theresultant device delivers sufficient power density to form visible marksin a metal (e.g. aluminum) container component despite the decreasedbeam size or aperture associated with the smaller mirror size.

Preferably, the laser light is delivered to the container region orcomponent as a series of high intensity laser pulses. Each pulse forms avisible ablated area or dot and the pattern of dots together make up thedesired symbol or image. Accordingly, to achieve a desired number ofcharacters or symbols in less than a predetermined period of time, thedevice must be capable of delivering all of the pulses needed forforming all of the desired characters within the predetermined timeperiod. In one embodiment, a laser device is provided which deliverspulses at a frequency of at least about 12 kiloHertz (kHz) whileproviding sufficient power that substantially all such pulses producethe desired spot ablation of the metal container component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial perspective view of a container end with a tabmarked according to an embodiment of the present invention;

FIG. 2A is a block diagram depicting components of a container tab stockmarking device according to an embodiment of the present invention;

FIG. 2B is a block diagram of steering components of the device of FIG.2A;

FIG. 3 is a partial plan view of partially-marked tab stock according toan embodiment of the present invention; and

FIG. 4 is a flow chart depicting a marking process according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Although the present invention can be used in marking many portions of acontainer or a container component and marking many shapes and styles ofcontainers, FIG. 1 depicts one example of a container 112 having amarking 114 positioned on a container-opening tab. In the depictedembodiment, the tab 116 includes a covered or web area 118 in thecentral digit-grasping portion of the tab 116 and, in this embodiment,it is a portion of the web region 118 which bears the marking 114. FIG.1 shows a configuration in which the tab 116 has been lifted 122 to avertical position, revealing the underside of the tab (the surfacevisible in FIG. 1) and, in the process, forming an opening 124 in thecan end 126. In the embodiment of FIG. 1, the underside of the tab whichis visible in FIG. 1 would normally be nonvisible prior to opening thecontainer, i.e. would be maintained adjacent the outer (public) surfaceof the container end 126. The upper surface of the tab is not visible inthe view of FIG. 1 but would be visible prior to opening the container.Accordingly, the embodiment of FIG. 1 can be used in connection withproviding prize or other promotional indicia or other situations inwhich it is not desired or not necessary for the markings to be visibleprior to opening the container. The present invention, however, can beused in connection with marking other surfaces of the containerincluding portions of the underside of the tab other than the centralweb 118, portions of the upper surface the tab, portions of inner orouter surfaces of the container end 126 (and/or the opposite end, notshown in the partial view of FIG. 1), and/or inner or outer surfaces ofthe container body 128.

When it is desired to provide markings on one or more regions of acontainer-opening tab 116, the markings, in one embodiment, are providedin conjunction with a tab-forming process. In many situations,tab-forming is accomplished by feeding a web of tab stock into a formingmachine which uses well known metalworking procedures for forming thesubstantially flat tab stock into the desired tab shape. Examples ofsome of the metalworking procedures which may be used include stamping,coining, folding, cutting and the like. For economy of expression,references below to tab-stamping or tab-forming should be understood toinclude these and other well known tab-forming processes and machines.

As depicted in FIG. 3, in one embodiment the tab stock 312 has a width314 (i.e. a lateral or x dimension 316) sufficient to form three tabsfrom a predetermined longitudinal length 318 a,b,c,d,e of tab stock 312(i.e. a length along the longitudinal or y dimension 322). Although thetab stock 312 may have great longitudinal length, such as a web with alength of 3000 meters or more, the tab stock 312 is dimensioned, and inparticular, has a width 314 such that each predetermined length 318 a,318 e contains sufficient material to form a plurality of tabs, and inthe depicted embodiment, sufficient material to form three tabs. Thus,predetermined length 318 a can be used to form one tab from each ofthree laterally arranged regions 324 a,b,c.

In one configuration, the tab stock 312 is fed or advanced to atab-stamping device in an intermittent fashion. According to suchintermittent feeding, the tab stock 312 is advanced longitudinally adistance equal to the predetermined distances 318 a,b,c,d,e during afirst (or “advancement”) period. Thereafter, the tab stock 312 is heldsubstantially stationary for a second (or “dwell”) period, during whichstamping and other operations are performed on one or more predeterminedlengths of the tab stock to form, e.g., three tabs. Thus, each cycle ofthe tab-stamping device includes an advancement period and a dwellperiod. These cycles are repeated, one after another, preferably forminga plurality of tabs (such as three tabs) at each cycle or stroke of thestamping machine. It should be understood that the stamping machine maybe configured to have a plurality of stations or operations e.g. suchthat, during any one cycle, a first predetermined length 318 isundergoing a first operation, such as cutting, while precedingpredetermined lengths 318 b, 318 c, 318 d, etc. are undergoing otheroperations such as coining, folding, and the like.

Preferably, the tab-stamping cycles are relatively short such asdefining a cycle time of less than about 150 milliseconds, preferablyless than about 100 milliseconds, in at least one embodiment, a cycletime of about 87 milliseconds (equivalent to a stamping machine having700 strokes per minute). In one embodiment, the dwell time is about ⅔ ofthe cycle time and accordingly, the dwell time may be, e.g., about 100milliseconds, preferably about 50 milliseconds or less.

In one embodiment, the desired markings are formed on the tab stockprior to reaching the stamping operations (i.e. the markings on anygiven region of the tab stock are formed before that region reaches thestamping device). By configuring the marking operation in conjunctionwith the stamping operation, registering or positioning the markings onthe tab stock so as to reside at the desired region of a finished tab isfacilitated.

In order to avoid distortion of the markings that might otherwise beassociated with the relatively high acceleration curves used during theadvancement phase of the cycle, it is preferred to achieve at leastsome, and, preferably substantially all of the marking during thestationary or dwell phase of each cycle. Accordingly, in thisembodiment, the dwell time defines the length of time (or “window”)available for making the desired markings on any given predeterminedlength 318 a, 318 b, 318 c, 318 d, 318 e of the tab stock 312. Accordingto the present invention, markings 326 a-f are made on the tab stock 312using laser light. Preferably the laser light is pulsed light, with eachpulse being available for forming a single spot or dot such that aplurality of spots are positioned to, together, give the appearance orimage of the desired characters or other markings. For example, foraluminum alloys typically used for tab stock, it is believed thatdelivering laser pulses will suffice to deliver sufficient power toachieve the ablation of aluminum necessary to provide visible spots. Inone embodiment, the tab stock is formed of an alloy available under thetrade designation 5042, e.g. from Aluminum Company of America or KaiserAluminium. Accordingly, the present invention is configured to achievedelivery of laser pulses, each with sufficient power to make a visibledot, sufficient in number to form the desired number and size ofcharacters (with the desired quality or resolution) within the dwelltime available for such marking considering any pulse non-application orblanking time e.g. used for accommodating relatively larger mirrormovements such as movements between characters or between sets ofcharacters.

In one embodiment, the device delivers pulses at a rate of about 12 kHzand produces at least 6, preferably at least nine characters of thedesired quality with a character or letter height 332 of about 0.125inches (about 3 mm) over a lateral range 334 of about 1 inch (about 2.5cm).

Thus, in addition to providing a sufficient number of dots within thetime window to form the desired size and quality of characters, thepresent invention is also configured to position those dots, as needed,across an area of tab stock having a lateral extent 334 of about 1 inchand a longitudinal extent 332 of about 0.125 inches, i.e., over an areaof about 0.125 square inches.

FIG. 2A depicts one embodiment of an apparatus which can be used formaking such markings within a time window of less than about 100milliseconds, preferably less than about 50 milliseconds. A portion 212of the device shown in FIG. 2 is used for generating a pulsed laser beam214 which is then steered by a portion of the device 216 to output alaser beam 218 along a path so as to position pulses of the beam forforming markings 326 as described above. The laser includes a lightsource/pumping component 222 positioned between mirrors 224 a,b todefine a laser cavity. Preferably a safety valve 226 interrupts lightoutput e.g. in the event of failure or container breach. A chopper 228provides the light in a pulsed or intermittent form. In one embodiment,a Nd:YAG laser provides an output of about 40 to 50 watts (appliedpower), with about 80% of such power being delivered to the tab stocktarget. Preferably the laser is configured to output laser light pulseswhich are relatively stable in the sense that there is relatively littlevariation in power from one pulse to the next and, preferablysubstantially all pulses have sufficient power to vaporize or ablate themetal target sufficiently to produce a visible spot or mark. Laserdevices that can be used in this regard include those available fromLaser of Orlando, Fla. A cooling unit 232 is coupled 234 to the lasergeneration region 212 to maintain the proper operating temperature ofthe laser generating unit. A computer 236 which may be, e.g., aworkstation-type computer preferably having a Pentium® or Pentium II®processor, outputs control signals 238 a, 238 b for controlling anx-steering galvanometer 242 a and a y-steering galvanometer 242 b,respectively, as described more fully below. One example ofgalvanometers that can be used for this purpose include galvanometersavailable from Cambridge Technology, Inc. of Watertown, Mass. The tabstock 312 is held at the desired distance from the laser and preferablyin a vibration-free manner such as coupling guidance/advancementcomponents 244 to a relatively vibration-free pedestal 246 such as aconcrete-filled or other high-mass pedestal, vibration-isolationmounting or the like. In this way, a portion of the tab stock 312 can beheld stationary during the dwell period for marking. As described above,during the advancement period of each cycle, the tab stock is advanced,using, e.g., drive rollers or the like, toward a stamping unit 248 as itis withdrawn from a tab stock coil 252 or similar source.

In the embodiment of FIG. 2B, the first steering galvanometer (e.g, ay-steering galvanometer 242 a) is coupled to a movable, e.g., pivotable,mirror 254. Galvanometer 242 a is coupled to the mirror 254 so that themirror 254 is pivoted 256 about a pivot axis 258 (perpendicular to theplane of the paper in the view of FIG. 2B) in such a manner that themirror 254, receiving the laser pulses, will reflect the pulses (toprovide first reflected laser light pulses) at an angle whose magnitudedepends on the pivoted position of the mirror 254. The first reflectedlaser light pulses are received by the second mirror 260 which iscoupled to a second galvanometer 242 b (e.g., an x-steering galvanometer242 b) so as to permit selectable pivoting about a second pivot axis 262(parallel to the plane of the paper in the view of FIG. 2B) forreflecting the pulsed laser beam (to provide second reflected laserlight pulses) toward the desired region of the tab stock 312. In theview of FIG. 2B, the pivot position of the y-steering mirror 254determines the position of the beam, (with respect to the tab stock 312)in a longitudinal or y direction 322 while pivoting of the x-steeringmirror 260 about the second axis 262 determines the position of thelaser pulses (with respect to the tab stock 312) in the lateral or xdirection 316.

In order to position the laser pulses as needed across the entirelateral extent 334 and longitudinal extent 332 needed to form a set ofcharacters 326 a, 326 b, 326 c as desired, within the dwell period, suchas within about 50 milliseconds, the mirrors 254, 260, and particularlythe x-steering mirror 260 (responsible for positioning through therelatively larger x range) must be moved quite rapidly. It is believedthat previous steering devices have been incapable of, at a reasonablecost, providing such rapid mirror positioning. According to oneembodiment of the present invention, rapid mirror positioning isfacilitated by providing relatively low mass mirrors. The mirrors, inone embodiment, are provided in a lightweight configuration primarily byproviding a relatively small surface or reflective area of the mirrors.In one embodiment, the mirrors have a nominal size or diameter of about5 mm, such as being a square or rectangle with at least one edge havinga length less than or equal to about 5 mm. The low mass mirrors providea low moment of inertia to assist in rapid mirror movement. Preferably,each of the mirrors presents a moment of inertia to the respectivegalvanometers of less than about 0.2 g/cm², preferably less than about0.1 g 1 cm², and more preferably less than or equal to about 0.08 g/cm².

Because the reflective surface area of the steering mirrors is reduced,the beam size or aperture of the laser light which can be effectivelydelivered to the tab stock is relatively small.

In order to position the laser pulses, which are preferably beingdelivered at a rate of about 12 kHz, to the desired position, it isnecessary to provide x and y control signals 238 a, 238 b which controlthe galvanometers 242 a, 242 b also at a rate of about 12 kHz.Preferably the computer 236 is configured (programmed) to output controlsignals to achieve the desired positioning at this rate as well as beingcontrolled to retrieve, create or select the desired characters orindicia 326 a-326 d as needed for the particular application (e.g.random or pseudo-random indicia for certain contest or promotionpurposes) and to make the character or indicia selections rapidly enoughto provide a new set of selections during each cycle of the stampingdevice 248. Although it is at least theoretically possible to increasethe lateral range 334 or longitudinal range 332 of the beam position byincreasing the distance e.g. of the tab stock 312 from one or bothmirrors, such increase in distance also increases the effect of beamdivergence and, thus affects power density delivered at the tab stock.For example, by decreasing divergence by 50% (e.g. by positioning thetab stock closer), spot size at the tab stock is reduced to half thespot diameter, thus halving the power delivered, but, because area isproportional to the square of radius, doubling the power density.However, increasing power density by providing for closer positioning ofthe tab stock requires more rapid mirror movements to maintain the samemarking speed (for a given range of character placement).

In operation, as depicted in FIG. 4, during one portion of the stampingcycle, the computer 236 selects the next nine characters which are to bemarked on the tab stock 412. When the dwell period of the stamping cycleis reached, the tab stock is held stationary 414 and the laser lightoutput is activated while the computer generates control signals toplace laser pulses at the desired respective x and y positions to renderthe desired visible markings 416. After the desired markings have beenmade, the laser pulses are interrupted 418 and, during the advancementportion of the cycle, the tab stock is advanced a predeterminedlongitudinal increment toward the stamping machine. Thereafter, thecycle is repeated 424 as needed to provide the desired number of markedtabs or until the tab stock is depleted.

In light of the information provided herein, a number of advantages canbe seen. The present invention is able to achieve markings of containersor container components at a relatively rapid rate, and, preferably,sufficiently rapidly to keep pace with other container or containercomponent forming processes so that the marking can be achieved withoutslowing or interfering with such processes. The present invention makesit practical and feasible to provide markings which can be readilychanged or customized, including markings which are different for eachcontainer or container component in a sequence of containers orcomponents. The present invention can achieve such rapid markingssubstantially without distortion or deformation of the markings andwithout weakening, piercing or damaging the container or containercomponent. The present invention makes it practical and feasible toprovide six or more, preferably nine or more, legible, 0.125 inches tallor larger characters distributed or positioned across the width of tabstock in connection with a tab-forming process during a relatively shorttime period such as a tab-forming dwell time, preferably within about100 milliseconds and more preferably within about 50 milliseconds. Thepresent invention makes it possible to steer the positioning of laserpulses having sufficient power to mark or ablate metal across a lateralextent of about one inch and a longitudinal extent of about 0.125 incheswithin a time period of less than 100 milliseconds, preferably less thanabout 50 milliseconds. The present invention provides for container orcontainer component marking which is less maintenance-intensive or morereliable than other marking procedures and devices and permits changesto markings without the need to stop or slow a container or containercomponent fabrication device or process. The present inventionfacilitates implementation of contests, sweepstakes or other promotionswhich involve providing indicia on components or containers preferablyon an undersurface of tabs coupled to containers, preferably so as to benon-visible prior to opening a container, e.g. awarding at least a firstprize (indicated one of such indicia) to a customer upon verifyingpresence of the prize indicium e.g. on a tab. Because the characters,indicia, symbols and the like to be marked can be designed/createdentirely (potentially) in software (i.e. without the need for orderingor creating dies or the like) the lead time involved between design of apromotion, game, or the like, taking of an order or other initiationevent, the time in which production can begin is substantially shortenedcompared to hardware-dependent procedures such as incising or embossing.

A number of variations and modifications of the invention can be used.Although the present invention provides for a cost-effective procedureand device which may include a laser that delivers sufficiently-poweredpulses at a rate of about 12 kHz, it is also possible to use the presentinvention in connection with other lasers, including lasers that have ahigher pulse rate or higher power, preferably with each (orsubstantially each) pulse delivering sufficient power to ablate orvaporize aluminum or other metal such as to provide a visible mark.Although a galvanometer-based beam steering procedure and device hasbeen described, other steering may be used including acoustico-opticalsteering in place of or in addition to galvanometer based steering,which offers the potential for steering which is at least partiallyindependent of the mass of mirrors or other components and, thus,potentially more rapid. Although a computer has been described inconnection with providing control or control signals for laser steering,other devices and procedures for providing control signals can be usedincluding digital signal processors (DSP) which are believed to offerthe potential for generating control signals at a relatively high rate,at least partially because of the elimination or reduction of ratedependency based on bus speed or the like.

Although embodiments have been described in regard to marking of stockused for forming tabs, the present invention can be used in connectionwith marking other portions of metal containers such as ends or endcaps, body or sidewall portions, container bottom portions and the like.

Although a particular container end shape as depicted in FIG. 1, thepresent invention can be used in connection with a wide variety of metalcontainers including beverage containers, food containers, aerosolcontainers and the like. Although the present invention has beendescribed in connection with marking of aluminum container or containercomponents, the present invention can also be used in connection withmarking other types of metal containers such as steel containers.Although the present invention has been described in connection withablating or vaporizing portions of the metal of a metal container, it isalso possible to use the present invention in connection with ablatingor vaporizing some or all portions of coatings placed on a metalcontainer, so as to provide markings that are visible by way of acontrasting color or texture. For example, it is possible to provide ametal container or container component which has been coated with acolored coating (such as by printing or painting) and to use the presentinvention to selectively remove or vaporize portions of such coatings toreveal at least some of the metal portion (or another coating)underneath. In this situation, it may be possible to use a lower-poweredlaser such as a CO₂ laser.

Although the embodiment of FIG. 1 depicts a tab having a web in thefinger grasp region, it is also possible to use the present invention inconnection with a tab in which a finger hole is provided in the fingergrasp region and in which markings are positioned on other portions ofthe tab.

Although the present invention has been described in connection withcertain markings which will typically be viewed or visible to consumerssuch as promotional or contest marking, advertising, logos, etc., it isalso possible to use the present invention in connection with markingswhich will typically be concealed such as being concealed under a foldof the tab or other container component. As one example, concealedmarkings may be used for security or verification purposes, e.g. toverify that a prize-indicating marking is genuine and not counterfeit.Although the present invention has been described in connection withproviding markings during a stationary or dwell time, it is alsopossible to use the present invention to make some or all markingsduring movement of the tab stock or other target substrate, particularlywhen the markings are security or internal markings or otherwise willnot normally be seen or used by the ordinary consumer (such that acertain amount of distortion may be acceptable).

Although the present invention has been described in connection withbeam steering which utilizes two separate mirrors, it is possible toprovide for beam steering which uses a single mirror (e.g. which ispivotable with respect to two independently controllable axes, and/orwhich is deflectable or deformable). Although the present invention hasbeen described in connection with a process which uses a single laserfor X riting all the desired markings during any given cycle (believedto be particularly useful when it is desired to provide markings in alow-cost manner), it is nevertheless also possible to use the presentinvention in connection with a system having two or more lasers such asfor writing different characters or different portions of characters soas to achieve a higher number of characters in a given amount of time.Although the present invention has been described in connection with aprocedure providing at least six legible characters, preferably at leastnine legible characters per cycle, the present invention can also beused in connection with devices or procedures which produce more orfewer characters.

In general, it is possible to use some aspects of the invention withoutusing others. For example, it is possible to provide for rapid markingof characters or other indicia without providing for randomly orotherwise changing the indicia with each cycle. For example, in view ofthe ability to rapidly change or modify the nature of the indicia ormarkings provided, the present invention can be used to provide markingswhich indicate time and/or date of manufacture, filling, sealing and thelike. Although the present invention has been described in connectionwith making markings e.g. for promotional, advertising, identificationor similar purposes, it is also possible to use the present invention inconnection with making lines, grooves, or other formations which may beat least partially functional or structural such as by using the presentinvention to create opening-defining scores in container ends and thelike. Although the present invention has been described in connectionwith placing markings on tab stock before the tab stock is formed, cutor attached to containers or container ends, it is possible to providethe steps in other orders such as marking tabs e.g. after folding butbefore cutting, after cutting but before attachment to containers, orafter attachment to containers.

The present invention, in various embodiments, includes components,methods, processes, systems and/or apparatus substantially as depictedand described herein, including various embodiments, subcombinations,and subsets thereof. The present invention, in various embodiments,includes providing devices and processes in the absence of items notdepicted and/or described herein or in various embodiments hereof,including in the absence of such items as may have been used in previousdevices or processes, e.g. for achieving ease and reducing cost ofimplementation.

The foregoing discussion of the invention has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the invention to the form or forms disclosed herein. Althoughthe description of the invention has included description of one or moreembodiments and certain variations and modifications, other variationsand modifications are within the scope of the invention, e.g. as may bewithin the skill and knowledge of those in the art, after understandingthe present disclosure. It is intended the appended claims be construedto include alternative embodiments to the extent permitted.

What is claimed is:
 1. A method for making metallic containers havingselectable patterns thereon, comprising: providing a container end;controlling laser light so as to ablate a desired region of at least acomponent of said container end wherein a selectable pattern is placedon said desired region and in which said component of said container endis a container-opening tab.
 2. A method, as claimed in claim 1, whereinsaid pattern defines a lateral range of at least about 1 inch andwherein said pattern is produced by said laser light in a period ofabout 50 milliseconds.
 3. A method as claimed in claim 1 furthercomprising attaching said container-opening tab to other portions ofsaid container end after said pattern is placed on said desired region.4. A method as claimed in claim 1 wherein said tab is formed using aprocess which defines a dwell time during which a workpiece, containinga region which is to be formed into said tab, is substantiallystationary and wherein all said pattern for said tab is produced by saidlaser light during said dwell time.
 5. A method as claimed in claim 1wherein said tab is formed using a process which defines a dwell timeduring which a workpiece, containing a section which is to be formedinto said tab, is substantially stationary, wherein said workpiece has awidth, wherein a first set of N tabs are formed from said width of saidworkpiece, N being greater than one, and wherein all patterns for saidfirst set of N tabs are produced by said laser light during said dwelltime.
 6. A method as claimed in claim 5 wherein N is at least
 3. 7. Amethod as claimed in claim 5 further comprising controlling said laserlight to produce all said patterns for a second set of N tabs within aperiod less than about 150 milliseconds after providing patterns on saidfirst set of N tabs.
 8. A method as claimed in claim 1 wherein said stepof controlling said laser light comprises using a computer to outputcontrol signals for controlling a path of said laser light.
 9. A methodas claimed in claim 1 wherein said step of controlling said laser lightcomprises using a digital signal processor to output control signals forcontrolling a path of said laser light.
 10. A method, as claimed inclaim 1, wherein: said pattern includes at least a first set of Mcharacters and wherein said M characters are produced by said laserlight in a period of less than about 100 milliseconds.
 11. A method asclaimed in claim 10 wherein at least one of said characters is at least0.125 inches in height.
 12. A method as claimed in claim 10 wherein saidstep of controlling comprises controlling said laser light such thatsaid M characters can be arbitrarily selected.
 13. A method as claimedin claim 10 further comprising repeating said step of controlling saidlaser light to produce at least a second set of M characters whereinsaid second set of M characters can be arbitrarily selected to bedifferent from said first set of M characters.
 14. A method as claimedin claim 13 wherein the period of time between producing said first setof M characters and producing said second set of M characters is lessthan about 150 milliseconds.
 15. A method as claimed in claim 1 whereinsaid container-opening tab is formed from a metal and wherein said laserlight delivers at least enough power to ablate a sufficient amount ofsaid metal to incise said metal so as to produce visible indicia.
 16. Amethod as claimed in claim 15 wherein said metal comprises an aluminumalloy.
 17. A method for laser marking a portion of a container,comprising: providing a first portion of a first container; providing asecond portion of a second container; and controlling laser light so asto ablate a desired region of said first portion of said first containerwherein a selectable pattern is placed on said desired region during adwell time of a cycle of operation while each of said first portion ofsaid first container and said second portion of said second container issubstantially stationary and during said dwell time, said second portionis subject to a forming operation by which said second portion isaltered, said dwell time being no greater than about 100 milliseconds.18. A method as claimed in claim 17, wherein: said forming operationincludes one of cutting, coining, and folding.
 19. A method as claimedin claim 17, further comprising: controlling said laser light so as toablate a desired region of said second portion of said second containerat a time different than said step of controlling said laser light so asto ablate said desired region of said first portion of said firstcontainer.
 20. A method as claimed in claim 17, wherein: said firstportion of said first container includes one of a container-opening tab,a container end and a container body.
 21. A method as claimed in claim17, wherein: said controlling step is conducted using a light pathdeflection system that includes at least a first movable component. 22.A method as claimed in claim 21, wherein: said first component includesa first mirror and said light path deflection system also includes afirst galvanometer and in which said first mirror presents a moment ofinertia to said first galvanometer of less than about 0.1 g/cm².
 23. Amethod as claimed in claim 17, wherein: said first mirror has a nominaldimension of less than about 5 mm.